Your wife is free to pull your plug and then marry someone else because she did not break the covenant. She is allowed to marry after you die.
She is not free to pull your plug after she has committed adultery while you are still alive because she has broken the covenant by committing adultery.
If you can't understand that simple reasoning...please ask your wife to pull the plug NOW.
Suppose my family and the government and a bunch of internet activists stopped my wife from pulling the plug? Her choices then become to either not move on with her life (unnaccetable to me) until a decades-long legal battle is resolved, or to "break" the marriage covenant. I'd want her to take the second option.